aggregate

问题 I have a query that's basically "count all the items of type X, and return the items that exist more than once, along with their counts". Right now I have this: Item.objects.annotate(type_count=models.Count("type")).filter(type_count__gt=1).order_by("-type_count") but it returns nothing (the count is 1 for all items). What am I doing wrong? Ideally, it should get the following: Type ---- 1 1 2 3 3 3 and return: Type, Count ----------- 1 2 3 3 回答1: In order to count the number of occurrences

问题 I have some problems designing the aggregate root. Here is how I see it in my mind :) Store (the aggregate root) -> Sales - A store create a sale every day -> Zones - A store is divided into zones -> Styles - A zone has x number of styles --> Colors - A style has x number of colors etc.. Now based on this my aggregate root would be the store. However if I were now to create a Repository around that, would it look something like this? public class StoreRepository() { Store GetById() {...}

问题 It's probably something silly I missed, but I try to concatenate a list of integers instead of summing them with: integerArray.Aggregate((accumulator, piece) => accumulator+"," + piece) The compiler complained about argument error. Is there a slick way to do this without having to go through a loop? 回答1: Which version of .NET? In 4.0 you can use string.Join(",",integerArray) . In 3.5 I would be tempted to just use string.Join(",",Array.ConvertAll(integerArray,i=>i.ToString())); (assuming it

问题 I have a table with an ID column and another column with a number. One ID can have multiple numbers. For example ID | Number 1 | 25 1 | 26 1 | 30 1 | 24 2 | 4 2 | 8 2 | 5 Now based of this data, in a new table, I want to have this ID | Low | High 1 | 24 | 26 1 | 30 | 30 2 | 4 | 5 2 | 8 | 8 As you can see, I want to merge any data where the numbers are consecutive, like 24, 25, 26. So now the low was 24, the high was 26, and then 30 is still a separate range. I am dealing with large amounts of

问题 Below is an example matrix: mat<- matrix(c(1,0,0,0,0,0,1,0,0,0,0,0,0,0,2,0, 2,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0, 0,0,1,1,1,0,0,0,0,0,0,0,0,0,0,0, 0,1,0,0,0,1,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,1,0,0,1,0,1,1,0,0,1,0,1, 1,1,0,0,0,0,0,0,1,0,1,2,1,0,0,0), nrow=16, ncol=6) dimnames(mat)<- list(c("a", "c", "f", "h", "i", "j", "l", "m", "p", "q", "s", "t", "u", "v","x", "z"), c("1", "2", "3", "4", "5", "6")) I want to group or bin columns and then aggregate data for each group. First, I would like to bin two

问题 To illustrate the problem we use a simple case: there are two aggregates - Lamp and Socket . The following business rule always must be enforced: Neither a Lamp nor a Socket can be connected more than once at the same time. To provide an appropriate command we conceive a Connector -service with the Connect(Lamp, Socket) -method to plug them. Because we want to comply to the rule that one transaction should involve only one aggregate, it's not advisable to set the association on both

问题 Hello Everybody I am pretty much completely new to R and any help is greatly appreciated. I have the following data (called "depressionaggregate") from 2004 until 2013 for each month: Month Year DepressionCount 1 01 2004 285 2 02 2004 323 3 03 2004 267 4 04 2004 276 5 05 2004 312 6 06 2004 232 7 07 2004 228 8 08 2004 280 9 09 2004 277 10 10 2004 335 11 11 2004 273 I am trying to create a new column with the aggregated values for each year for each quarter (i.e. 2004 Q1, 2004 Q2 etc.). I have

问题 I hope someone is able to help me with what is, at least to me, quite a tricky algorithm. The Problem I have a List ( 1 <= size <= 5 , but size unknown until run-time) of Lists ( 1 <= size <= 2 ) that I need to combine. Here is an example of what I am looking at:- ListOfLists = { {1}, {2,3}, {2,3}, {4}, {2,3} } So, there are 2 stages to what I need to do:- (1). I need to combine the inner lists in such a way that any combination has exactly ONE item from each list, that is, the possible

问题 Does anybody know how to aggregate by NA in R. If you take the example below a <- matrix(1,5,2) a[1:2,2] <- NA a[3:5,2] <- 2 aggregate(a[,1], by=list(a[,2]), sum) The output is: Group.1 x 2 3 But is there a way to get the output to include NAs in the output like this: Group.1 x 2 3 NA 2 Thanks 回答1: Instead of aggregate() , you may want to consider rowsum() . It is actually designed for this exact operation on matrices and is known to be much faster than aggregate() . We can add NA to the

问题 I need a standard deviation function in SQLite. I have found one here: http://www.sqlite.org/contrib?orderby=date but its part of an extension file to SQLite. I've never installed one of these before and I don't know how to. I found this existing function, load_extension , at http://www.sqlite.org/lang_corefunc.html, but I don't understand what the parameters X and Y are. Basically, I need someone to give me a step by step guide on how to install the aggregate extension file. Can anyone do